Eccentbic fob



L. SYKES. comma ma PNEUMATIC ooLs AND THE LIKE.

- APPLICATION FILED 0CT.30, 1918. l1 ,318,818, Patented Oct. 14,1919.

HHWMMMMM Armen/frs ,UNITED STATES PATENT OFFRE-f LEWIS sir/Kits,` or cAMnEN, VNriw anasninssieNon, YBY DIBECTHAND iviEsNE nssIGNf MENTS, 'To KELLER 'PNEUMATrc Toon COMPANY, or. GRAND' HAVEN, iviicHIGAN, A

`coisuoanriroN' or MICHIGAN; s

EccEN'rnrc Fon-PNEUMATIC ,Toons AND THE-LIKE'.` f`

" lf, '-1?ateinieu` ont.; 143919 Application mea octobero, 1918i. seriaiNo. 260,237@

i To all 'whom it may concern.'

Be it known tliatL'Lnwis Sriinmacitiiz'en of the .United States, residing in theV city and county of CamdemState of New Jersey,

.have invented a new and usefulEccentric for 'Pneumatic Tools and the like, vofwhich the following is a specification.

My invention relates, generally` I to rpneu? Y' matic drillsor air tools, and consists` particularly in a novel construetionof an4 eccentric and driving'meclianism therefor, andV my object is to produce an eccentric of. a

strong and durable character in conjunction with a .strong and durable coacting driving connection, whereby the breakage which has heretofore been' v,experienced z devices of this character, will be reduced to a minimum orentirely eliminated. y A l It is well known thatpneumatic drills or air tools and similar implements-which lare used in boiler-shops, Shipyards, structural metal plants and. the like, .frequently re-V ceive very severe usage,as they are fre-' quently operated byfinexperienced and unskilled workmen, which. results in tliebreakage of various parts thereof, and my present invention is particularly designedto remedy defects heretofore existing particularly in the eccentric and driving `connections common to the eccentric andthe crank shaft in pneumatic drills of the generalcharacter hereinabove referred to. I

It has heretofore been the. practice in pneumaticdrills or airrtools ofI the general. character to which my invention relates, to

employ an eccentric for actuating the distribution valve, having a driving connection.

with the top of the crank shaft andV to .slot

said eccentric. across the-top thereof 4in 'al .line at fone.` side ofthe .diameter thereof` Vand, parallel to said diameter.. The presence 0f this sloi-J .reduced the strength Lof .the` eccen-` tricb'ody .very materially, since small arcshaped area is formed at one side of said vtop -in proximity to the walls of which slot are located the flats or driving faces at the top'Y of the crank shaft, whereby the eccentric ,Y

is rotated andthe proper reciprocations of thevalve'efl'ected through the eccentric strap and its adjuncts.

` In thisf. prior apart or Vaway by the continual pressure and vibration of the flats or driving faces on the art construction, this,Y arc-shaped area-` ,at o nel side of' the cecentric; top Pin ,practice `becomes. gradually Y spread.

upper'end of the crank shaftfthereby. causing aslightexpansion of theout'er upper wallsfof the eccentric,-the'reby creating'V a, clamping or binding action within the .eccentric strap which .connects the eccentricY to thefdistribution valve, whichresults in u excessive :wear and create this spreading action at the'small Varc-shaped area atl one side of the slot in the top ofthe eccentric,"V

which causesthe eccentricfto rise orl jump Vaway from its seat, thereby raisingv the ec.-v ceiitricstraps andbreaking the Vpins off the en d of the distributionvalve, andin certain instances, I have foundtlie clearance or p lay between the top ofthe eccentric and, the under side vface of the bonnet which, forms. a closure for the top vof the drill c asing was' suflicient tol allow the eccentric to jump away.l

fronithe driving seat-for about half a `revo-2'V lution, Orl/more' yand -then drop back again into the wrong position jfojr tiine',.;so.,that'V the vtiming Yof the throw of the valve was altered to. such an extent that -it will cause the drill to run backward; Y

In ,orderto remedy the foregoing defects, I have devised a novel construction offan" eccentric' havino' astrengthening bofss onthe. top the'rof to talle upany clearance between thetop of theeccentric and theunderside` of the bonnet, whichfprevents-theeccentric 5;.: i

from junipingrup and binding inthe eccei'if tric strap, and in Vlieu ,of -a slotextendingall theway across and weakeninglthe topof the eccentric,lbroacha hole inthe-eccentric about three-quarterspfdts depthfroinj the Y top downwardly, said broachedhole termif nating in la roundbottom bearing, rwhich -is of lesser diametergthan the topjournalbeai'-, Y i ing of theV crank shaft, the latter having .a 1 Vshoulder orgabutinent formed thereonnpon which the eccentric rides.

The flats or driving faces -attlie top-.of

crank shaftV are .of the, saine contour as the holethrough the eccentric and are; prolonged to form an extended and durable bearing in the hole of the eccentric, which VlatterV is de-l` tachable therefrom, so that an abundance of material is provided inthe proper place for bothnthecrank shaft and the eccentric, both of which are thereby very much strengthened, so that breakage of the eccentric,

spreading of the eccentric strapsand breakv ing the valve pins, are not only reducedV to a minimum, but will be found t0 be entirely obviated by my invention.

To the above ends my invention consists of a novel construction of a pneumatic drill or air tool having an eccentricof novel construction intermediate the distribution valve and the driving faces of the crank shaft.

It further consists in prolonging in a novel manner the driving faces common to the upper end of the crank shaft and the broached hole in the eccentric.

It further consists of a novel construction of an eccentric having a boss on the upper portion thereof adapted to reduce clearance and to contact with the under surface 0f the bonnet, said boss and eccentric having a hole broached therethrough conforming to the flats or driving faces of the upper end of the crank shaft.

It further consists of other novel features of construction, all as will be hereinafter fully set forth.

For the purpose of illustrating vmy invention, I have shown vin the accompanying drawings one form thereof which is at present preferred by me, since the same will give in practice satisfactor 1 and reliable results, although it is to be un erstood that the various instrumentalities of Which my invention consists can be variously arranged and organized and that my invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described. l

Figure 1 represents a vertical, sectional view of an eccentricV and Vin elevation the coacting driving portion of a crank shaft embodying my invention, the pneumatic drill in conjunction with which my novel eccentric is employed being shown diagrammatically or in dotted-lines. j

Fig. 2 representsV a side elevation, in ,de-

tached position, of a portion of they upperv end of a crank shaft, With my novel eccentric in section thereon.l Y

Fig.V 3 represents a perspective vievv of my novel eccentric in detached position,v

Fig. 4 represents a bottom plan vvievv of figure 3. fr,

Fig. 5 represents in perspective the upper or driving end of the crank shaft, showing the elongated bearing or Hats or driving faces thereon coacting with my novel eccentric.

Similar numerals' of reference indicate corresponding parts.

Referring to the drawings 1 designates the casing of a rotary pneu ceives the drill,V reamer or other Working tool, the foregoing elements being of any standard conventional type, so that a further detailed description thereof is unnecessary. Y

7 designates a bonnet, which may also be of any conventional type and is secured to the casing 1 in any desired manner. The crank shaft 5 'aty its upper end 'terminates in the journal 8, which revolves in a suitable ballbearing and has the round bearing 9 of lesser diameter above it, thereby forming 1 ashoulder or abutment 10, on Which my novel 'eccentric hereinafter referred to rests.

rllher top or end extension 11 of the crank shaft 5 constituting the driving member thereof for the eccentric, is faced off to produce the parallel fiats or driving faces 12, which terminate at the shoulders 13, said driving faces extending about three-quarters of the Way through the eccentric 14, which has the holes 15 therein to lighten it. The eccentric 14 consists of a cylindricalblock having` eccentrically positioned in it, the hole 16, which is broache'd therethrough, the top of the eccentric having an annular boss 17,

through which said hole 16 extends, said boss 17 being adapted to be seated in a recess 18 in the underside of the bonnet 7. The hole 16 at its lower end terminates in an annular recess or seat 19, which fits over the annular bearing`9 above the crank shaft journal 8 when the parts are assembled as seen in Figs. 1 and 2.

rlhe eccentric 14 is engaged by an eccentric strap 20'of the usual construction, which actuates the distribution valve 21, Which controls in the usual manner the admission and exhaust of motive fluid to actuate the pistons and thereby the crank shaft.

It will be seen that when the parts are assembled, the boss or annular bearing '17 preferably Vcontacts with or is seated against the underside of recess 18 of the bonnet 7 and the bottom of the eccentric rests on the yshoulder 10j above the [journal 8i bf the crank shaft, so that any up and down play of the eccentricl on the flats or driving faces 12 of the crank shaft is practically eliminated.

It will be seen from the foregoing, that the'provision of the eccentric boss 17 gives greatly added strength to the eccentric body and particularly the upper portion of the eccentric, and if for any reason'a little cleari ance between the topof the eccentricy and the under side of they bonnet 7 ymust be allowed, 'said boss suiices toV take up this clearance or reduce it to a minimum,which A ing said hole about three-quarters of the distance from the top of the boss 17 downy wardly and making the flat-s or driving faces (S0 what I claim as new and desire to secure 12 correspondingly elongated, as will be understood from Figs. 1, 2 and 5, an abundance of material is provided in the proper place and there is no liability of the eccentric body spreading under any conditions so as to cause binding or breaking of the eccentric straps, nor can the eccentric rise away from its seat l0, or raise the eccentric straps or breakthe pins off the ends of the distribution valve, as is evident.

It will be ap arent that when the bonnet 7 is removed, t e eccentric 141 which is de-y tachable vertically from the driving faces 12 of the crank shaft, can be readily slipped` oft' upwardly from said driving faces for the purposes of inspection, replacement or repair.

I have deemed it unnecessary to describe in detail the cycle of operation of the pneumatic drill, per se, as the same will be apparent to those skilled in the art,.it being understood that the distribution valvecontrols the flow of the motive fluid to the cylinders 2, whereby the pistons 3 are reciprocated, the reciprocations of the piston actuating the crank shaft, the lower end of whidli transmits power to the spindle 6, while the upper end of said crank shaft rotates the eccentric 14 in the manner described, said eccentric controlling the reciprocations of said'valve 21.

For the sake of clearness, I have shown the elements which constitute the novel features of my invention in full lines, the old structure of the prior art, as in Fig. l, being shown dotted. n It will now be apparent that I have devised a novel and useful construction of-anV eccentric for pneumatic toolsA and the like, which embodies the features of advantage enumerated as desirable'in the statement ofV the invention and the above description, and

. while I have, in the present instance, shown parting from thespirit or scope ofthe in- Y vention or sacrificing any of its-advantages.l Having thus Y described. my invention,

by Letters Patent, is I Y 1. In a pneumatic drillorair tool, a cas- Gopiel of this patentvmay be obtained for ing, a bonnet therefor, a piston driven crank shaft in said casing, an eccentric detachably mounted on an end of said crank shaft and having an eccentrically positioned boss on the topthereof adapted to seat against the under side of said bonnet, there being a hole extending through said boss andeccentric to a point near the bottoni of the latter, to form an elongated bearing for the driving portion of said crank shaft, and means actuated by said eccentric to control the admission of motive iiuid to said drill.

y 2. In a pneumatic'drill or air tool, a crank shaft, means for actuating the latter, a journal bearing on the upper end of said crank shaft, -a round bearing of lesser diameter above said journal bearing, therebyV forming an eccentric supportingshoulder, the top of said-crank shaft being provided with; Eflats or driving faces, an eccentric adapted to rest on said shoulder and having an eccentrically located boss on the top thereof,y said eccentric .havingv a hole broached through said boss-aiid body into a seat in the bottom of said body, the coni tour of said hole corresponding to the contour of the driving faces at the-top of said crank shaft, and means for the distribution of the motive fluid controlled by said eccentric.

3. In a pneumatic drill or air tool, the' forming the eccentric supporting shoulder 10, the top of said crank shaft terminating in the iiats or drivingl faces V12, with an eccentric resting on said shoulder and detacliable therefrom, and having'a bottom seat 19 to receive said crank shaft Vbearing 9, said eccentric having the eccentric boss 17 on the top thereof and the hole 16 therein extending-through said boss downwardly to said bottom seat'19, said eccentric hole having the flats or driving faces 22 and the portion of said crank shaft flats 12 engaging said faces 22 occupying about three-quarters of the thickness of said eccentric.

4. As an improved article of manufacture,

an eccentric for a pneumaticrdrill or airl tool, composed of a body having an eccentric boss 17, at the top thereof, said-body having seat, said eccentric hole having the flat driving faces 22 adapted to coact withsimilar drivingfaces ofa crank shaft.

at the bottom thereof an annular seat 19 and a hole 16 therein extending from the top of said boss through said boss and body to said 1201 Lewis sYxEs. fr

ve cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

